How to Fix a Cracked Model B Block?

[rogeroadster]

I have a model B engine which I bought as a core to be rebuilt. It is a diamond block that has been re-sleeved back to standard bore and has bronze (or possibly copper) cam bearing inserts. It has not been magnafluxed or pressure tested or even cleaned yet. It has what looks very much like a crack running up from the water inlet boss. Because it is otherwise such a good candidate for re-build I thought I'd repair this crack by stop drilling the end of it, veeing it out and brazing it. Does anyone have any experience with this type of problem and could offer advice on fixing it?